Targeted Detoxification of Aflatoxin B1 in Edible Oil by an Enzyme-Metal Nanoreactor.

Mycotoxin contamination is an important issue for food safety and the environment. Removing mycotoxins from food without losing nutrients and flavor components remains a challenge. In this study, a novel strategy was proposed for the targeted removal of aflatoxin B1 (AFB1) from peanut oil using an amphipathic enzyme-metal hybrid nanoreactor (PL-GOx-Fe3O4@COF) constructed with covalent organic frameworks (COFs) which can selectively adsorb AFB1. Due to the confined space provided by COFs and the proximity effect between GOx and Fe3O4, the detoxification of AFB1 is limited in the nanoreactor without affecting the composition and properties of the oil. The detoxification efficiency of AFB1 in the chemoenzymatic cascade reaction catalyzed by PL-GOx-Fe3O4@COF is six times higher than that of the combination of free GOx and Fe3O4. The AFB1 transformation product has nontoxicity to kidney and liver cells. This study provides a powerful tool for the targeted removal of mycotoxins from edible oils.

Biodegradation of Aflatoxin B1 in Peanut Oil by an Amphipathic Laccase-Inorganic Hybrid Nanoflower.

Aflatoxin B1 (AFB1) contamination is an important issue for the safety of edible oils. Enzymatic degradation is a promising approach for removing mycotoxins in a specific, efficient, and green manner. However, enzymatic degradation of mycotoxins in edible oil is challenging as a result of the low activity and stability of the enzyme. Herein, a novel strategy was proposed to degrade AFB1 in peanut oil using an amphipathic laccase-inorganic hybrid nanoflower (Lac NF-P) as a biocatalyst. Owing to the improved microenvironment of the enzymatic reaction and the enhanced stability of the enzyme structure, the proposed amphipathic Lac NF-P showed 134- and 3.2-fold increases in the degradation efficiency of AFB1 in comparison to laccase and Lac NF, respectively. AFB1 was removed to less than 0.96 µg/kg within 3 h when using Lac NF-P as a catalyst in the peanut oil, with the AFB1 concentration ranging from 50 to 150 µg/kg. Moreover, the quality of the peanut oil had no obvious change, and no leakage of catalyst was observed after the treatment of Lac NF-P. In other words, our study may open an avenue for the development of a novel biocatalyst for the detoxification of mycotoxins in edible oils.

Co-Immobilization of Enzymes and Metals on the Covalent-Organic Framework for the Efficient Removal of Mycotoxins.

Mycotoxin is an important contaminant in food and the environment. The conventional methods for detoxification of mycotoxins are plagued by high chemical consumption, secondary pollution, and specific equipment required. In this study, we propose a chemoenzymatic cascade reaction for mycotoxin removal in an effective and green manner using an enzyme-metal hybrid catalyst synthesized by compartmental co-immobilized glucose oxidase (GOx) and Fe3O4 nanoparticles (NPs) on a flower-shaped covalent organic framework (COF). The GOx-Fe3O4@COF hybrid catalyst exhibits excellent activity in mycotoxin removal due to the enrichment of mycotoxins in COF and the cooperative catalysis between GOx and Fe3O4 NPs. The degradation efficiency of aflatoxin B1 (AFB1) in the chemoenzymatic cascade reaction catalyzed by GOx-Fe3O4@COF is 3.5 times higher than that in the Fenton reaction catalyzed by Fe3O4@COF. The GOx-Fe3O4@COF hybrid catalyst is highly active in a wide pH range of 3.0-7.0, overcoming the limitation of the Fenton reaction that can only perform below pH 3.0. This study provides a powerful tool for the efficient removal of mycotoxins.